So you've got what?....another 50 years?

Don't fret it. In any electronics device, the most failure prone components are - in order:

Anything mechanical - use eventually wears down the friction parts beyond their working tolerance.
Connectors - over time, corrosion and vibration conspire to change what was once an excellent solid electrical connection into a dodgy one in which the connection is intermittent.
Adjustable components - eg trimming potentiometers and the like. For pretty much the same reasons as the connectors.

So I'd be suprised if in normal use, the flash died before the front buttons or the knob's rotary encoder. Or the sled docking connector, Home power adaptor, RCA outputs, display connector, HD connectors etc.

As I said, just avoid deliberately putting the unit through 100K power cycles.